IBM 402

If using 40-year-old hardware seems quaint, how about a machine so old it's from a generation of devices that predate digital computers.

In 2013, a US filtration firm in Conroe, Texas was still doing its accounting and stock taking using an IBM 402, a 1948 tabulating machine that reads data from punched cards.

At the time, Sparkler Filters was planning to phase out the system, not least because there was only a single punch card technician left to carry out repairs.

Image: Ed Thelen / http://ibm-1401.info/402.html

IBM Series/1

Thought nuclear power plants running on 1970s computers was bad? How about a 40-year-old system in charge of US nukes.

The antiquated tech in question is the US Department of Defense's Strategic Automated Command and Control System, which co-ordinates the US's nuclear forces, including the operation of intercontinental ballistic missiles and bombers. Despite its critical role in US defense, it still runs on an IBM Series/1, a computer so old it uses 8-inch floppy disks that store millions of times less data than a modern USB stick.

Image: CBS News

Apple I

This is a working piece of Apple's history, handbuilt by Steve Wozniak when the company -- today worth $495bn -- was a three-man operation working out of a garage.

Windows 3.1 PC

Remember what Microsoft Windows used to look like in the early 1990s?

Workers at Paris' busy Orly airport certainly do, mainly because as of 2015 some were still forced to use Windows 3.1, which was released back in 1991. French authorities promised to replace the airport's aged PC, which links air traffic control systems with France's main weather bureau, after the system crashed last year.

Image: Imgur

WordStar 4.0

It's not just computers that are kept running long into their dotage.

While the violent fantasy world of Game of Thrones draws inspiration from real-life medieval events, series author George RR Martin is also helping to keep computing history alive.